Mathematics - 2014-12-06 (page 1 of 6)

robjohn

00:13

It would be nice if this comment were upvoted. Then it would be visible without expanding the comments.

Jacopo Notarstefano

Done.

robjohn

@JacopoNotarstefano Thanks!

Time to take a dog to the park and then have dinner... BBL

Jorge Fernández

00:43

0

Q: A binomial inequality

I've tried both expanding the binomials as well as trying to deduce something from the hypergeometric distribution, but I don't see how to prove: $${N\choose n}^{-1}\sum_{i\geq j}{M\choose i}{N-M\choose n-i}{i\choose j}\leq {n\choose j}\left(\frac{M}{N}\right)^j.$$

That question made me vomit

Twink

01:22

:'(

Jorge Fernández

02:28

I hate it when people delete questions with your answers on them !!

JessicaK

02:40

I thought you couldn't delete a question once it has been answered?

Jorge Fernández

haha, I wish

JessicaK

A user just edited one of my questions in a manner that does not change anything at all other than the style of the raw tex code...

Jorge Fernández

what a douchebag

JessicaK

Uh, I don't feel that strongly about it.

Jorge Fernández

oh, I thought you did

wow, you have about a tenth of my reputation and about a twentieth of my activity. That means you get about twice as many upvotes on average than I do.

well not so much, but substantially more upvotes per post.

JessicaK

02:56

I find the most upvoted posts generally contain popular linkable material so it's not necessarily a good thing.

The best material I've read usually has <5 upvotes

Andrey Kaipov

03:51

Does the set of all integers fail to satisfy the Peano axioms because we cannot properly define "1" so that $S(n) = 1$ is always false? Right, or not right?

Tom Cruise

I thought the integers satisfy Peano's axioms?

why is a sock puppet staring at me

@AndreyKaipov are you Russian?

Andrey Kaipov

I would hope they do, since there's a bijection from N and Z, but I'm having a hard time seeing why that successor axiom applies.

Yup!

@Tom

@TomCruise Are you actually Tom Cruise? lol

Tom Cruise

Unfortunately no

I saw the movie Andrei Rublev so thats why I guessed russian

Andrey Kaipov

Darn ): I was hoping to squeeze into the movie business.

Tom Cruise

What is the successor axiom again?

Andrey Kaipov

04:01

For each $n\in\mathbb{P}$, $S(n) \not= 1$.

The positive integers start at 1, but where do the integers start, ya know

Tom Cruise

oh

I guess $\mathbb Z$ does not satisfy the axioms

There is a bijection between $\mathbb N$ and $\mathbb Z$ but this bijection does not preserve the operations of $+/-$ with respect to $\leq $.

maybe I've had too much to drink though ;)

Andrey Kaipov

So it looks like if two sets satisfy Peano's axioms, there's a bijection between them, but not the other way around?

Tom Cruise

I would say there is even an isomorphism

so that the successors are preserved by the bijection

Andrey Kaipov

Okay that's something to think about! Thanks!

Tom Cruise

no problem, just throwing ideas out there

final exams next week, ughhhhh

Twink

04:13

@TomCruise ? :|

Tom Cruise

@Twink whats happening?

Twink

Tom Cruise doesn't wanna come out of the closet

Tom Cruise

I dont want to give my real name

Twink

But Tom Cruise doesn't wanna come out of the closet!

did you know?

Tom Cruise

did I miss something in the news?

Twink

04:17

it's not news, everybody knows that

Tom Cruise

ah

I'm just chillin to some CSNY tonight

tired of maths

Twink

Tom Cruise is gay

Andrey Kaipov

Yeah there was something missing in the news

Tom Cruise

Tom Cruise was married to Nicole Kidman

Twink

@AndreyKaipov did you know that Tom Cruise is gay?

Yes many gays are married to women

because they don't want to come out of the closet

Andrey Kaipov

04:20

an absence of a certain ornithological piece

Tom Cruise

you talkin about birds?

Twink

mais mon dieu qu'il est beau

Andrey Kaipov

I think I went to France once

Tom Cruise

do either of you have a phd or are you trying for a phd?

my French is bad

Andrey Kaipov

just a lost undergrad

Tom Cruise

04:22

"but my god it is beautiful" ?

Twink

loool

google translator sucks

Tom Cruise

no that was my own translation

my French sucks

Twink

oops!

if you say so... lol

why did you translate il=it?

Tom Cruise

@AndreyKaipov you can always go to grad school later

oh you're right il=he

so you think Tom Cruise is hot

Twink

yes

Tom Cruise

04:24

thats my new translation ;)

Twink

handsome

and hot too, lol

don't you think so?

Tom Cruise

its funny because I was just watching Eyes Wide Shut earlier tonight

He was good looking in the 80s/90s but not so much now

Twink

I like Tom Cruise but he is gay

Tom Cruise

@Twink are you a student?

Twink

no

Tom Cruise

04:29

then why do you care about math?

Twink

why not?

Tom Cruise

you just teach yourself for fun?

Twink

nope

I just like this chat room

there's nice people

Tom Cruise

you clearly care about math though

and know some

Twink

I hate math

I'm very bad

Tom Cruise

04:31

but you have asked questions here

Twink

I never understand anything

how do you know that?

are you stalking me?

who are you?

Tom Cruise

cause I click on your profile

lol

Twink

yes I've asked because I know nothing

Tom Cruise

come on

you clearly know some graduate-level math

Twink

who are you?

tell me who you are

now

Tom Cruise

04:33

I am just looking at your profile

I can see the questions you asked

Twink

are you a student?

Tom Cruise

you can click my profile if you want

Twink

do you care about math?

Andrey Kaipov

tempest don't take the axe

Tom Cruise

@AndreyKaipov what?

Twink

04:35

@TomCruise are you a student?

answer the same questions you asked me

Tom Cruise

yes I am a graduate student

currently struggling

Twink

where

in what country

Tom Cruise

in USA but I cant say where :)

Twink

why not?

Tom Cruise

someone here might track me down

Twink

04:36

what would he do that?

and what would be the problem if they tracked you?

Tom Cruise

nothing I just like being anonymous

Andrey Kaipov

people are dangerous

Tom Cruise

I am famous like Tom Cruise

what if I am really Tom Cruise, and I am secretly a math enthusiast...

Twink

and why are you so famous?

are you a genius?

Tom Cruise

I wish

Twink

04:40

then what makes you so famous?

Tom Cruise

I would love to solve an unsolved problem

that is what motivates me

Twink

that's a good goal

Tom Cruise

yes but it is very hard

Twink

my goal in life is to marry an old and very rich man

Tom Cruise

most problems are unsolved for a reason... and some really smart people have worked on them already

Twink

04:42

so he dies soon and I get all the money

Tom Cruise

are you gay?

Twink

why can't you think I'm a girl?

Tom Cruise

you dont have to answer that

not many girls in math

Twink

you're sexist

there are many girls here in MSE

Tom Cruise

but if you are a girl we should meet

;)

Twink

04:43

what for?

Tom Cruise

the usual stuff

anyway...

Twink

what's the usual stuff?

Tom Cruise

back to math

Twink

Do you meet all girls from the chats?

Tom Cruise

lol, no

Twink

04:45

then I don't understand

Tom Cruise

I'm just kidding

Twink

but I'm not a girl, I'm gay like Tom Cruise

Tom Cruise

are you working on any open problems?

Twink

no

I'm not good solving problems

Tom Cruise

I think you are a student

Twink

04:46

:)

Tom Cruise

most people on MSE are students

Twink

not true

there are a lot of teachers too

Tom Cruise

yeah

but I dont think you are a professor

Twink

why not?

Tom Cruise

because of your answers

Twink

04:48

I might be an elementary school teacher...

Tom Cruise

oh yeah

Twink

maybe yes.. maybe not...

Tom Cruise

ok

my guess now is that you graduated with an undergrad degree in math last year and now you are a teacher

Twink

lol

you're so wrong xD

Tom Cruise

darn

Twink

04:50

I'm nothing... just a silly gay guy on the chat room...

Tom Cruise

no you know some math

maybe just for fun, or maybe because you're a grad student

Twink

if that's what you wanna think....

maybe..

we'll never know :p

Tom Cruise

I guess not

you asked a question about measure theory

Twink

stop stalking me :p

Tom Cruise

so that leads me to believe you are either in a very good undergrad program or some graduate program

lol, ok

what is your favorite area of math?

Twink

04:54

I hate all areas of math

what about you?

Tom Cruise

you liar

I like topology

Twink

I'm not lying

I hate all areas of math because I'm very bad at all of them

Tom Cruise

then why dont you choose a different major?

Twink

how do you know I already chose a major?

Tom Cruise

you are confusing to me

Twink

04:59

that's what I want to do :p

Transcript for

$Mathematics$ Mathematics